Electrical FS boxes for outdoor use are typically mounted on the exterior of buildings for providing convenient access to electrical outlets and other electrical devices such as switches and timers. Conventional FS boxes typically are a simple rectangular box configuration with a back wall and four side walls. When being mounted to a building, a rectangular hole must be cut in the substrate in order to mount the electrical box to the building. Cutting into the substrate creates a costly and time consuming repair job for the installer as he must typically caulk around the perimeter of the electrical box to seal against rain penetration between the box and the substrate. Although the caulk is meant to seal around the box, it is difficult to obtain a perfect seal making it likely that rain or water could seep behind the siding surrounding the box. Furthermore, cutting into the substrate can disrupt and damage the building's insulation layer that typically resides just under the substrate. There is also the problem of potentially damaging electrical wiring that is behind the area of the cut.
What is needed is an electrical box assembly that minimizes the need to cut a hole in the substrate and that accommodates siding in a manner that eliminates water seepage behind the siding. The electrical box assembly should provide protection against rain and weather to a receptacle mounted therein while an electrical cord is plugged into the receptacle. The electrical box should furthermore include a cover member that is collapsible, to reduce the profile of the electrical box when it is not in use.